WEAKENING OF MIROKUBecause of Miroku's burden, he needs to be careful with how much he uses his wind tunnel. However, with the final days coming near, Miroku has been using it an awful lot. Sango forces Miroku to back down because she cares.
As we've previously discussed, Miroku has to be careful when he uses his Wind Tunnel too much because eventually it will break open too much and suck him in. However, as the final days are coming near, Miroku realizes that in order to defeat Naraku, he must use his Wind Tunnel at any opportunity to win. Previous to this, Miroku opened up his Wind Tunnel a bit too much, causing people to hear the wind even with the fabric over the hole. This means that if he uses it without thought, he will be sucked in. When Naraku appears before them, Miroku feels like he has no choice but to open it up again. Although Sango and friends try their best to stop him, he continues. Miasma bugs come, making Miroku intake too much poison. Blood starts to rush from his eyes, and his body begins to weaken. Miroku collapses to the ground, allowing Naraku to escape. Sango rushes over to him, sobbing out. Kikyou is able to slightly heal Miroku by pouring some of her life force into him. This prevents him from dying, but doesn't completely allow him to fight like normal.
Sango now realizes that she needs to step up her game, no matter what, in order to reassure that Miroku won't use his Wind Tunnel again for awhile. However, the two aren't let off easy. Demons attack them again in Episode 12 of the Final Act, causing Miroku to have to fight in order to save Sango. Sango gets angry seeing Miroku hurt once again in order to attempt to protect her, so she realizes that she has to destroy her Hiraikotsu by putting corrosive poison on it to kill the demon attacking them. They both collapse after, and InuYasha finally comes to defeat the rest of the demons. To read more about this specifically, head over to the ultimate sacrifice page!